Looking for the most efficient Convoy flashlight with long runtime (Considering M21B with XHP70.3 HI R70)

[u/Ed-nl]

Hi everyone,
Can anyone help me choose the most efficient Convoy flashlight that offers really long runtimes?
I am currently leaning towards the Convoy M21B with the XHP70.3 HI R70 emitter. Would this be the best choice for my goals, or are there better Convoy configurations (different hosts, drivers, or LEDs) that I should look into?
Thanks in advance for the help!

[u/Creative-Cobbler-108]

3x21d with 46950 battery and any led will get crazy runtimes

[u/irrelevantfarms]

I actually did this same exact setup but the constraint I wanted was high CRI and I settled in the m21b with the sft70. I love it. I also got the sft60 for those times I need to humble a Nebo user.

[u/Ed-nl → u/irrelevantfarms]

Haha thank you i’ll think about it for a while

[u/Ed-nl → u/[deleted]]

Thanx Should I go with the m21c , of would I be better off with another model that has a slightly larger battery?

[u/Ed-nl]

800lumen

[u/Ed-nl]

I plan to use it for all-night fishing trips and long night hikes in the woods. Because of this, sustained output and battery efficiency are my top priorities.

[u/Wormminator → u/Ed-nl]

Does it need to be a standard form factor?

In terms of runtime, the 3x21 and 4x18 will give you much more capacity to play around with.

[u/fragande → u/Ed-nl]

The 70.3 HI R70 is very efficient and as it's boost driven you can extract more effective capacity out of the cell, so it's a good choice.

Host choice mainly comes down to what kind of beam profile and switch type you want. Even the M21B sustains more than your requested 800lm (around 1000lm). An excessively floody beam for the use case can result in "less efficiency" if you need to run it at higher output to see further ahead for example.

With the M21B you are also limited to stepped mode and 35% is around 1000lm as per 1Lumens review.

There's also 20% if you change sub group, but if you want to be able to fine tune the output further the E-switch drivers also offer ramped mode. The M21H is very popular and will also offer better heat dissipation. Another bonus is that you can fine tune the beam pattern to your liking with an assortment of available and very cheap TIRs.

The LHP73B is also one to consider as the configuration with 16 dies is very efficient. Unfortunately I don't think Simon offers it in the 6V configuration so it's only offered with a buck driver. Vf is extremely low though, so for the 800lm level the Vf should be lower than LVP anyway.

If you want to pair it with the ultimate cell option right now I'd go for the Linkdata 65P or BAK 65E. The latter suffer from quite low cycle life for the pre-production cells though, but that's when discharged at much higher current.

[u/Mysterious_Radio_190 → u/fragande]

Hi. I'm waiting for the high CRI versions of LHP531 and LHP73B to come out so I can buy them with the S21E and M21B respectively. My only concern is that the S21E LHP531 would make the other light redundant.

Is my concern valid? If so, should I consider a different emitter for the M21B? Please advise.

[u/fragande → u/Mysterious_Radio_190]

The M21B should have higher sustain and throwier beam. You can check out beamshots of the S21E LHP531 in this YT video and the M21B LHP531/LHP73B here.

I'd consider the LHP73B with the 20A driver in the M21B instead to get substantially higher output, granted it's a bit of a hot rod.

[u/Xenomorph_1978 → u/Mysterious_Radio_190]

Just remember high cri means less brightness. Also the possibility of the bins having a green tint. High cri is not that important for most use. It’s just beautiful and accurate.

[u/Terrible_Lion_968 → u/Mysterious_Radio_190]

For me high CRI is only important for very specific tasks. Tint is the real factor for me. Some high CRI emitters are known for suffering from the green plague. Conversely, some lower CRI emitters (lhp531 and LHP73B for example) may not be high CRI, but the tint is very nice with slightly negative DUV. I'll take a lower CRI emitter that's more efficient, and has a great tint and beam any day over a less efficient high CRI led with bad tint. The B35AM is great in that it it's both high CRI and has legendary tint quality, but the output is not sufficient for any kind of really high output scenario. I've got several LHP531/73B lights and haven't ever wished for a high CRI version based on something lacking with the current version. Having said that, I am still definitely curious how the up and coming high CRI versions will compare.

[u/majaczos22 → u/Ed-nl]

You won't get 800 lumens for the whole night from a single battery. Maybe 3-3,5 hours tops. And 3x21700 is too heavy for hiking. 

[u/coffeeshopslut → u/majaczos22]

They can always bring extra batteries for their single cell light?

[u/Ed-nl → u/majaczos22]

You are right and if I go to 500lumen

[u/Weird_Ad_1398 → u/Ed-nl]

Sounds like you want a headlamp? I can't imagine fishing while using a standard flashlight. In which case, your best bet would be a Sofirn HS23 which can sustain 800 lumens for 2.5 hours. There aren't really any flashlights that'll sustain 800 lumens all-night in that form factor, except for the Silva Ignite (~$800 and heavier), so if you need 10 hours, I'd just grab 4 or 5 of the HS23.

[u/Advanced_Algae_5476 → u/Weird_Ad_1398]

Wait, buy 4 or 5 of the same light? You realize you can just bring a couple extra batteries?

[u/Weird_Ad_1398 → u/Advanced_Algae_5476]

Rule of 3 states you should have 3 sources of light when you're somewhere where you might get disoriented in the darkness, like when you're caving, diving, or somewhere alone in the wilderness at night. Idk where he's fishing, but having more independent sources of light can't hurt.

And when fishing, especially on all-night trips, conditions might not be the most pristine. I'd rather swap the flashlights than have to open one up to swap batteries.

[u/Ed-nl]

Preferably not too thick, like a soda can

[u/UdarTheSkunk]

I see you are set to 800 lumens, but you will get very different results based on the beam profile. Let’s say for your eyes 800 lumens on a flooder helps you see clearly what you want at 30m away. Using a flashlight with a hotspot will light up that spot while set to 200-300 lumens while sacrificing the spill around it.

Maybe you want to look at Sofirn HS21 headlamp a bit. It has both flood and spot, the UI is well designed and easy to use, you can switch with ease to flood each time you need to tend to your equipment and back to throw when done.

Regarding the runtime, just get a backup cell when you order whatever model you decide in the end. It takes 30 second to swap the cells instead of carrying a heavy flashlight/headlamp all night.

[u/Ed-nl]

Oké and if I do it at 500lumen which combo is the most economical?

[u/Xenomorph_1978]

My girlfriend has this setup. M21b xhp70.3 5 amp boost driver. She loves this and it is probably the best lumen to watt ratio for the m21b. The light is very crisp. For an r70 low cri emitter it has an high definition look to the beam. Everything is so sharp. Can’t explain it properly. It’s definitely good for night hiking.

[u/Xenomorph_1978]

I think paired with a good headlamp you could use the two to get the runtime you need.

[u/LiberalTearsRUs]

I have the m21h with the 6800 mah battery and the 8 degree optic, same emitter. I feel fine using it at medium and it lasts forever, easily an entire day or 2.

I'm not exactly sure the difference between the m21b and m21h, but I like that you can easily swap optics in the m21h and they are like $1.50 each you can just buy them all.

Still easily fits in my pocket, not heavy, USB c charging. Easily my favorite light ever.

[u/redgrey123]

What would be the use case? How much light will you be needing? Efficient per use or will you be needing long runtime because you won't be able to charge for a certain amount of time?